Piles/Hemorrhoids:

Piles are hemorrhoids that become inflamed. Hemorrhoids are masses, clumps, cushions of tissue in the anal canal - they are full of blood vessels, support tissue, muscle and elastic fibers.

Although Hemorrhoids are thought of as unpleasant inflammations, we all have them. It is when the hemorrhoidal cushions become too big (inflamed) that problems occur - when this happens they are called piles or pathological hemorrhoids.

Put simply, "piles" are the swollen ones that are painful and cause problems, hemorrhoids can refer to the swollen ones (pathological hemorrhoids) or simply the normal structure. However, in most cases these days, the words piles and hemorrhoids are nearly always used interchangeably.